Use callbacks for items, monsters and status effects

Previously, global function names were defined in the respective XML
definitions of items, monsters and status effects. This was reasonable when
they all had the same state, but now they're sharing the single global
Lua state.

Now the Lua API provides access to the ItemClass, MonsterClass and
StatusEffect instances, on which callbacks for both standard and custom
events can be explicitly set.

Reviewed-by: Erik Schilling

1 files changed, 16 insertions, 7 deletions

diff --git a/src/scripting/luautil.h b/src/scripting/luautil.h
index 049276fe..2fc7543a 100644
--- a/src/scripting/luautil.h
+++ b/src/scripting/luautil.h
@@ -31,12 +31,14 @@ extern "C" {
 #include <set>
 #include <vector>
 
-#include "game-server/map.h"
-
 class Being;
-class NPC;
 class Character;
+class ItemClass;
+class MapObject;
 class Monster;
+class MonsterClass;
+class NPC;
+class StatusEffect;
 class Thing;
 
 // Report script errors and interrupt the script.
@@ -105,10 +107,16 @@ public:
     /**
      * Pushes a userdata reference to the given object on the stack. Either by
      * creating one, or reusing an existing one.
+     *
+     * When a null-pointer is passed for \a object, the value 'nil' is pushed.
      */
-    static int push(lua_State *s, T *object)
+    static void push(lua_State *s, T *object)
     {
-        if (!UserDataCache::retrieve(s, object))
+        if (!object)
+        {
+            lua_pushnil(s);
+        }
+        else if (!UserDataCache::retrieve(s, object))
         {
             void *userData = lua_newuserdata(s, sizeof(T*));
             * static_cast<T**>(userData) = object;
@@ -118,8 +126,6 @@ public:
 
             UserDataCache::insert(s, object);
         }
-
-        return 1;
     }
 
     /**
@@ -138,7 +144,10 @@ private:
 
 template <typename T> const char * LuaUserData<T>::mTypeName;
 
+typedef LuaUserData<ItemClass> LuaItemClass;
 typedef LuaUserData<MapObject> LuaMapObject;
+typedef LuaUserData<MonsterClass> LuaMonsterClass;
+typedef LuaUserData<StatusEffect> LuaStatusEffect;
 
 
 NPC *getNPC(lua_State *s, int p);